1. Field of the Invention
The present invention is directed to novel transient pro-drugforms of certain xanthine derivatives, and more particularly, xanthine derivatives useful in the treatment of dermal inflammation.
For the purposes of this application, the term "pro-drug" denotes a derivative of a known and proven prior art xanthine compound (e.g., theophylline), which derivative, when administered topically to a warm-blooded animal, "cleaves" in such a manner as to release the proven drug form in the dermal tissue thereof.
The term "transient" denotes dermal enzymatic and/or chemical hydrolytic "cleaveage" of the compounds of the instant invention in such a manner that the proven drug form (parent xanthine compound, e.g., theophylline) is released and the remaining "cleaved" moiety remains nontoxic and metabolized in such a manner that nontoxic, metabolic products are produced.
2. Description of the Prior Art
The development of pro-drug forms of certain xanthine compounds such as theophylline was initially carried out in order that such compounds could be used in the treatment of psoriasis. The antipsoriatic use of the compounds of Formula (I) is diclosed and claimed in applicants' parent application, previously identified, the subject matter of which is incorporated herein by reference. Quite unexpectedly, it has now been determined that these compounds exhibit a dermal anti-inflammatory activity as well.